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Old December 31st 05, 12:38 AM posted to rec.radio.amateur.antenna
Allan Jeal
 
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Default AH4 tuner in the middle of an offset fed dipole

Many thanks for your reply Bruce, your comments are very encouraging. I'm
glad that you made the point -

of antenna tuners can't tune the 1/2 Wave Resonante Frequency of the
connected antenna. So, one must carefully consider just where the
1/2 Wavelength Resonance Point is, and place it in a portion of the
spectrum that your not going to want to transmit.


I beleive that this same note is made in the AH4 documentation, thanks for
the reminder, I'll look back at this. I'll also consider your thoughts re
decoupling. And thanks for the tip on the Google search. I have actually
tried the search on Google but may have been too quick to give up. Will do
it again.

Cheers and have a great New Year
Allan


"Bruce in Alaska" wrote in message
...
In article ,
Bob Miller wrote:

On Fri, 30 Dec 2005 15:31:59 +1100, "Allan Jeal"
wrote:

Is it possible to get some fairly brief opinions without causing a war
or
even arguments ....
Is it likely to damage an Icom AH4 auto antenna tuner if the "antenna"
terminal is attached to one leg of a V (resonant at 14Mhz) and the earth
terminal is connected to the other leg of the V (resonant at 7Mhz)
without
any additional grounding. Is there any reason to swap the legs around.
Assume 100 watts max. It would be helpful if any opinions came from
those
who are familiar with the internals of the AH4. It would also be helpful
if
any repondents understood that others could have a differing opinion. de
VK2DQC, Allan. tnx


If you do a Google search for the AH-4 -- there used to be someone
with a page that showed it hooked up to a dipole, using the ground lug
for one of the dipole elements.

bob
k5qwg


I have used similar setups in commercial service all over alaska.
We used SEA1612B Autotuners feeding twin Morad 2600 Loaded whips
in a dipole configuration. The only caviate that I would put out
is, that you might think about decoupling the Coax Feedline and
Power Leads by wrapping them in bifilar fashion on a suitable
torriod core. The above systems are still in use 15 years later,
and doing just fine on frequencies from 2.0 Mhz all the way up to
26 Mhz. the other thng that you must figure on, it that these type
of antenna tuners can't tune the 1/2 Wave Resonante Frequency of the
connected antenna. So, one must carefully consider just where the
1/2 Wavelength Resonance Point is, and place it in a portion of the
spectrum that your not going to want to transmit.


Bruce in alaska (AL7AQ)
--
add a 2 before @